Worldwide availability of wireless services has created a demand for wireless network phones that are operable worldwide. In different regions of the world, there are different frequency allocations. A phone that is operable in each of the different regions requires either multiple antennas or multiple bandwidth antennas that cover the different frequency allocations. Multiple bandwidth antennas are a better option because wireless network portable phones benefit from compact antennas. Additionally, a multiple bandwidth antenna requires fewer parts, which is both more efficient and cost effective.
Performance of compact single bandwidth and multiple bandwidth antennas is dependent upon repeatable manufacturing. A preferred component in multiple bandwidth antennas is a helical radiator, which offers compact physical length. Mechanical tolerances for the manufacture of helical radiators have become more exacting as the electrical performance demands of a helical radiator have changed to permit multiple bandwidth antenna designs. Maintaining proper dimensions on a helix, e.g., the pitch, diameter, and length, is difficult using conventional spring making machines. This is especially true in a multiple pitch helix antenna. Moreover, maintaining proper dimensions on a multiple pitch helix during manufacture of the assembled antenna is difficult using conventional assembly. It is also important to have an antenna assembly that is simple to manufacture, as this reduces manufacturing costs. Thus, there is a need for an improved antenna assembly including a multiple pitch helical radiator that achieves dimensional stability during the manufacturing process.